class Solution:
    def uncommonFromSentences(self, s1: str, s2: str) -> List[str]:
        words1 = s1.split()
        words2 = s2.split()
        words1Count = {}
        words2Count = {}
        for word in words1:
            words1Count[word] = words1Count.get(word, 0) + 1
        for word in words2:
            words2Count[word] = words2Count.get(word, 0) + 1
        result = set()
        for word, count in words1Count.items():
            if count == 1 and word not in words2Count:
                result.add(word)
        for word, count in words2Count.items():
            if count == 1 and word not in words1Count:
                result.add(word)
        return list(result)
